As many as 66% of systemic lupus erythematosus (SLE) patients have
been reported to have cognitive deficits. These deficits are often
associated with information processing speed and working memory.
Similarly, processing speed and working memory impairments are the
hallmark of cognitive dysfunction in multiple sclerosis (MS). The Paced
Auditory Serial Addition Test (PASAT) places high demands on processing
speed and working memory. Fisk and Archibald, however, demonstrated
that the total score of the PASAT does not accurately reflect
impairments in these cognitive processes. They found that MS patients
used a chunking strategy to obtain correct responses and reduce the
cognitive demands of the task. In the present study, PASAT performance
was examined for 45 SLE patients and 27 controls using alternative
scoring procedures. Although the total number of correct responses did
not differ between SLE and controls at the 2.4 or 2.0 s presentation
rates, SLE patients had fewer dyads (correct consecutive responses)
than controls at the faster rate, and more chunking responses than
controls at both rates. Disease activity, disease duration, depression,
fatigue, and corticosteroids could not account for these differences.
The findings suggest that SLE patients, like MS patients, chunk
responses more often than controls, and that this scoring procedure may
better reflect the working memory and processing speed deficits present
in SLE. (JINS, 2004, 10, 35–45.)